Telephone-transmitter.



A. A. JAHNKE. TELEPHONE TRANSMITTER. APPLIOATION FILED NOV.18, 1910.

Patented Oct. 24, 1911.

ATTOR N EY Jays INVENTOR a. Q,/Mu

UNITED TATES ATENT FFTG.

ALBERT A. JAHNKE, OF RICHMOND, CALIFORNIA, ASSIGNOR, BY MESNE ASSIGNMENTS, TO NATIONAL WIRELESS TELEPHONE & TELEGRAPH 00., A CORPORATION OF THE TERRITORY OF ARIZONA.

TELEPHONE-TRANSMITTER.

Specification of Letters Patent.

Patented Oct. 24., 1911.

T 0 all whom it may concern.

Be it known that I, ALBERT A. JAHNKE, a citizen of the United States, residing at Richmond, in the county of Contra Costa and State of California, have invented new and useful Improvements in T elephone- Transmitters, of which the following is a specification.

The present invention relates to improve ments in telephone transmitters, its object being to provide a transmitter of great simplicity of construction and effectiveness in operation.

In the accompanying drawing, Figure 1 is a vertical section of the transmitter; Fig. 2 is a cross section thereof on the line 2 2 of Fig. 1; Fig. 3 is an enlarged longitudinal section showing the ports for the conducting material; Fig. 4 is a view at right angles to Fig. 3; Fig. 5 is a horizontal section on the line 55 of Fig. 3.

Referring to the drawing, 1 indicates a casing to which is secured, as shown at 2, a telephone mouth piece 3. Between said casing and mouth piece is clamped a diaphragm 4, to the center of which is secured a stem 5. Said stem slides, with the vibratory movement of the diaphragm, in a bearing 6, at the center of a vertical conduit 7 both the stem and conduit being made of insulating material, such as glass or lava. Extending in said conduit to within a short distance of said bearing respectively from above and below the same are conducting wires 8 of a transmission circuit 9, said transmission circuit being thus interrupted between the adjacent ends of said wires. The stem 5 is formed with a vertical transverse hole 10 therethrough which is adapted to register with the lower end of a contracted portion 11 of the conduit. In the normal position of the transmitter, when the diaphragm is stationary said hole 10 is midway between the position in which it is fully in register with said lower end of the contracted portion of the conduit and the position in which it is completely out of register therewith. In this position, a stream of a conducting fluid of a certain size is caused to constantly flow through the hole, as from an elevated tank 12, the size of the stream being limited by the extent of that portion of the hole 10 which is in connection with the upper half of the conduit 7. When the diaphragm is relatively to its bearing and thereupon upon the vibrations of the diaphragm. Hence the variations in the electric current produced will correspond with the vibrations of the diaphragm. Opening horizontally through said bearing is a second conduit 13, which, at its end adjacent to said bearing, is reduced to a size much less than that of the lower portion of the upper conduit 7.

In the stem 5 is formed, transversely to the hole 10 and connecting with said hole, a second hole 14 of much smaller diameter, and corresponding in size withthe adjacent end of the conduit 13. The effect of movement of the hole 14L with reference to the conduit 13 is similar to the hole 10 with reference to the conduit 7. But I supply said conduits 7 and 13 with fluids of different conductivities. The conduct 7 may be supplied with water, while the conduit 13 is supplied, as from a tank 16, with salt or dilute sulfuric acid. The result is that, in accordance to the proportionate extent with which the holes 10 and 14: register respectively with the conduit 7 and the conduit 13, to such an extent does the conducting fluid of great conductivity commingle with the conducting fluid of small conductivity, and therefore conductivity of the transmission circuit is caused to correspond with the vibrations of the diaphragm.

It is evident that the wires 8 can be adjusted so that the distance between them may be increased or diminished as required.

I claim 1. A telephone transmitter comprising a tubular conduit for conducting a fluid stream in the transmission circuit, a diaphragm, and means connected with said diaphragm for varying a cross-sectional area of said conduit, substantially as described.

2. A telephone transmitter comprising a diaphragm, conducting wires of a transmission circuit having ends adjacent to one another, a tubular conduit for connecting saidends by a column of fluid therein, and

means for varying a cross-sectional area of said conduit in accordance with the vibrations of the diaphragm, substantially as described.

3. A telephone transmitter comprising a diaphragm, connecting wires of a transmission circuit having ends adjacent to one another, a tubular conduit for connecting said ends by a stream of fluid constantly flowing in said conduit, and means for varying a cross-sectional area of said conduit in accordance with the vibrations of the diaphragm, substantially as described.

4. A telephone transmitter comprising a diaphragm, conducting wires of a transmission circuit having ends adjacent to one another, means for connecting said ends by a stream consisting of a mixture of two fluids of different conductivities, and means for varying the part of the fluid of greater conductivity mixed therewith in accordance with the vibrations of the diaphragm, substantially as described.

5. In a telephone transmitter, in combination with a diaphragm, a stem of insulating material attached thereto having a transverse aperture, a conduit for fluid, the aperture in the stem being adapted to variably register with said conduit in the vibration of the diaphragm, and terminals of an electric Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

transmission circuit in said conduit, substantially as described.

6. In a telephone transmitter, in combination with a diaphragm, a stem attached thereto of insulating material, a bearing for said stem also of insulating material, an aperture through said stem, a conduit adapted to register with the end of said aperture in the motion of said stem produced by the vibrations of the diaphragm, and conductors forming parts of an electric transmission circuit in said conduit on opposite sides of said stem, substantially as described.

7. In a telephone transmitter, the combination of a diaphragm, a stem secured thereto having two apertures intersecting each other, a bearing for said stem, conduits connected to said bearing, adapted to respectively register with said apertures, and conducting wires in one of said conduits separated by said stem and forming part of an electric transmission circuit, substantially as described.

In testimony whereof I have hereunto set my hand in the presence of two subscribing witnesses.

ALBERT A. JAHNKE. Witnesses FRANCIS M. IVRIGHT, D. B. RIcIIAnDs.

Washington, D. C. 

